Annual or perennial; leaf-blades flat or rolled. Spikelet: glumes 1-nerved or rarely the lower 3-5-(-7)-nerved; floret callus obtuse to pungent or bidentate; lemma convolute or involute; awns with or without a column, persistent or deciduous, the branches glabrous, flat or terete, sometimes the laterals reduced or rarely suppressed. Caryopsis terete, or grooved when lemma involute, the embryo 1/3 its length.